Did you know there are different types of asthma, such as allergic asthma, non-allergic asthma, exercise-induced bronchoconstriction [BRAHN-koh-kahn-STRIK-shun]? Another subtype of asthma you may not have heard of is called eosinophilic [EE-oh-sin-oh-FILL-ick] asthma. It is sometimes called “e-asthma” or “eos asthma” for short.

It is a type of asthma where you have increased inflammatory cells called eosinophils [EE-oh-sin-oh-FILLS] in the airway. It usually affects adults and can often be severe. More than 27 million people in the United States have asthma and about 10% of them have poorly controlled, severe asthma. Many of these people could have eosinophilic asthma. It is important to know if you have this type of asthma because it affects your treatment options.  

What Is Eosinophilic Asthma?

Eosinophilic asthma is a type of asthma that is caused by high levels of white blood cells called eosinophils in the airways of the lungs. The purpose of these white blood cells is to help you fight infections. Sometimes your body produces these immune cells in higher amounts. They overreact and can cause inflammation in the body, including in the lungs. People who have high levels of eosinophils can have increased swelling in the airways which can lead to asthma symptoms.

Eosinophilic asthma is a type of severe asthma, which can cause more frequent attacks. It usually starts in adulthood and may not respond to treatment with a common asthma medicine called an inhaled corticosteroid.  Often it is hard to know the exact cause for this type of asthma. Adult asthma usually affects more women than men. But eosinophilic asthma affects them at about the same rate.

If you have eosinophilic asthma, you can have allergic or non-allergic asthma triggers. Other types of asthma, such as allergic asthma, are commonly triggered by specific allergens, such as animal dander, mold spores, dust mites, and environmental allergens in the air.

How Do You Treat Eosinophilic Asthma?

Your doctor may do several tests to confirm your type of asthma. This may include checking your mucus or saliva for eosinophils, checking your blood eosinophil count, or doing a test that checks your breath for nitric oxide gas. Your doctor will also ask you about your past medical history, current and past symptoms, as well as any current and/or history of allergies. If your doctor diagnoses you with eosinophilic asthma, understanding this unique type of asthma is important to help you manage symptoms and have a better overall quality of life. Allergists and pulmonologists are the main types of medical specialists who evaluate and manage this lung disease.

Current management of eosinophilic asthma begins with standard guideline-based therapy. For example, people with asthma may be prescribed these types of medicines:

• A controller medicine treats airway swelling. It’s usually an inhaled corticosteroid. This is a maintenance medicine that controls and prevents asthma symptoms. They are generally safe, well-tolerated, and meant to be used regularly – even daily if prescribed.
• A quick-relief medicinehelps relieve symptoms when they occur by relaxing bronchospasms [brahn-ko-spaz-uhmz]. This is when muscles tighten and squeeze around the airways.
• A combination medicine has both quick-relief and controller medicines in one inhaler used for both short-term relief and control.
• A leukotriene modifier is a controller medicine that helps decrease inflammation in the lungs. Leukotrienes are chemicals produced by the immune system. They can add to the inflammation in the lungs caused by eosinophils.
  
  

Depending on how often and how severe your symptoms are, you may take these medicines every day or as needed. Your health care provider should develop a clear, written, and understandable action plan for the effective management of asthma symptoms.

For some people with eosinophilic asthma, common controller medicines may not work well enough on their own to control asthma symptoms. Once your doctor looks at your tests, medical history, and current symptoms, the next step is to make a plan for your treatment. You can work with your doctor to see if you need to add a targeted therapy. This type of asthma treatment is known as a biologic, or monoclonal antibody therapy.

Biologics target specific immune cells or molecules (pathways that are part of your immune system) to block swelling and inflammation and, in turn, reduce symptoms. You get these therapies as a shot or by IV every few weeks or two months, depending on the treatment.

Current biologic options for eosinophilic asthma include:

• Benralizumab
• Dupilumab
• Mepolizumab
• Omalizumab
• Reslizumab
• Tezepelumab-ekko
  
  

How Does Eosinophilic Asthma Affect Quality of Life?

If you have uncontrolled asthma, no matter the type, you are at higher risk for emergency room visits, hospital stays, or death. If you have severe asthma, you may have symptoms every day and go to the emergency room more often than people with well-controlled asthma. Severe asthma can limit your ability to do even simple tasks, can be debilitating, and can decrease your overall quality of life. Knowing the subtype of severe asthma you have (like eosinophilic asthma) may be very important for treating your uncontrolled asthma.

A study by the Asthma and Allergy Foundation of America (AAFA) in 2017 found that people with severe, uncontrolled asthma have greater emotional, social, and financial burden of disease. But not all people with severe, uncontrolled asthma are aware of what type of asthma they may have or that biologic treatments exist that may control their asthma better and improve their quality of life. This is an issue you should be aware of and discuss with your health care provider.

If you have asthma, talk with your doctors specifically about how asthma negatively affects your day-to-day life. Let them know what you hope to achieve with treatment. Ask them if you are a potential candidate for biologic asthma treatments. See a board-certified allergist or pulmonologist if possible.

We also encourage health care professionals to work closely with their patients to understand the many ways severe asthma affects your quality of life. Talk about specific risks and benefits of potential asthma treatments. Together, people with asthma and their support teams can develop a shared understanding of asthma management and treatment goals.

Medical Review: May 2024 by John M. James, MD